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Liquefaction-induced lateral spreading in Christchurch and surrounding suburbs during the recent
Canterbury Earthquake Sequence (2010-2011) caused significant damage to structures and lifelines
located in close proximity to streams and rivers. Simplified methods used in current engineering
practice for predicting lateral ground displacements exhibit a high degree of epistemic uncertainty, but
provide ‘order of magnitude’ estimates to appraise the hazard. We wish to compare model predictions to
field measurements in order to assess the model’s capabilities and limitations with respect to
Christchurch conditions.
The analysis presented focuses on the widely-used empirical model of Youd et al. (2002), developed
based on multi-linear regression (MLR) of case history data from lateral spreading occurrence in Japan
and the US. Two issues arising from the application of this model to Christchurch were considered:
• Small data set of Standard Penetration Test (SPT) and soil gradation indices (fines content FC,
and mean grain size, D50) required for input. We attempt to use widely available CPT data with
site specific correlations to FC and D50.
• Uncertainty associated with the model input parameters and their influence on predicted
displacements. This has been investigated for a specific location through a sensitivity analysis.